A digital signal computer, or digital signal processor (DSP), is a special purpose computer that is designed to optimize performance for digital signal processing applications, such as, for example, fast Fourier transforms, digital filters, image processing and speech recognition. Digital signal processor applications are characterized by real time operation, high interrupt rates and intensive numeric computations. In addition, digital signal processor applications tend to be intensive in memory access operations and require the input and output of large quantities of data. Thus, designs of digital signal processors may be quite different from those of general purpose processors.
One approach that has been used in the architecture of digital signal processors is the Harvard architecture, which utilizes separate, independent program and data memories so that the two memories may be accessed simultaneously.
Although the Harvard architecture provides acceptable performance, the need exists for further enhancements to the performance of digital signal processors. In particular, the need exists for increased computation rates, improved direct memory access (DMA) operation and multiprocessor configurations. Additional desirable features include increased integration of peripheral circuitry into the digital signal processing chip, so that the overall cost and complexity of the system is reduced.